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Exposure to an 890-MHz mobile phone-like signal and serum levels of S100B and transthyretin in volunteers

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Söderqvist F, Carlberg M, Hansson Mild K, Hardell L · 2009

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Cell phone radiation at typical exposure levels may weaken the blood-brain barrier within an hour of use.

Plain English Summary

Summary written for general audiences

Researchers exposed 41 volunteers to cell phone radiation for 30 minutes and measured blood proteins that indicate blood-brain barrier damage. One protein increased significantly after exposure, suggesting cell phone radiation may temporarily weaken the brain's protective barrier.

Why This Matters

This study addresses one of the most concerning potential mechanisms of EMF harm: disruption of the blood-brain barrier. The blood-brain barrier is your brain's critical defense system, preventing toxins and pathogens from entering brain tissue. The finding that transthyretin levels increased after just 30 minutes of exposure at 1.0 W/kg suggests this barrier may be compromised by cell phone radiation. What makes this particularly relevant is that 1.0 W/kg falls well within typical cell phone SAR levels, which can reach up to 1.6 W/kg in the US. The researchers were appropriately cautious about clinical significance, but the reality is that any compromise to the blood-brain barrier deserves serious attention. This study adds to growing evidence that EMF exposure creates biological effects at levels regulators consider 'safe,' reinforcing why you should minimize your exposure through simple precautions like using speakerphone and keeping devices away from your head.

Exposure Details

SAR
1 W/kg
Source/Device
GSM 890 MHz
Exposure Duration
30 min

Exposure Context

This study used 1 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 1 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern rangeFCC limit is 2x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 890 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 890 MHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The aim of this study was to test, using peripheral markers, whether exposure to a mobile phone-like signal alters the integrity of the human blood-brain and blood-cerebrospinal fluid barriers.

A provocation study was carried out that exposed 41 volunteers to a 30 min GSM 890 MHz signal with a...

Repeated blood sampling before and after the provocation showed no statistically significant increa...

The clinical significance of this finding, if any, is unknown. Further randomized studies with use of additional more brain specific markers are needed.

Cite This Study
Söderqvist F, Carlberg M, Hansson Mild K, Hardell L (2009). Exposure to an 890-MHz mobile phone-like signal and serum levels of S100B and transthyretin in volunteers Toxicol Lett. 189(1):63-66, 2009.
Show BibTeX
@article{f_2009_exposure_to_an_890mhz_187,
  author = {Söderqvist F and Carlberg M and Hansson Mild K and Hardell L},
  title = {Exposure to an 890-MHz mobile phone-like signal and serum levels of S100B and transthyretin in volunteers},
  year = {2009},
  
  url = {https://www.sciencedirect.com/science/article/abs/pii/S037842740900246X},
}

Quick Questions About This Study

A 2009 study found that 30 minutes of 890 MHz radiation exposure significantly increased transthyretin levels in blood, suggesting temporary changes to the blood-brain barrier. However, researchers noted the clinical significance remains unknown and called for additional studies with more specific brain markers.
Research by Söderqvist and colleagues found no statistically significant increase in S100B protein levels after 30 minutes of 890 MHz cell phone radiation exposure. However, they did observe significant changes in transthyretin protein levels 60 minutes post-exposure.
A controlled study of 41 volunteers showed transthyretin protein levels increased significantly 60 minutes after 890 MHz cell phone radiation exposure ended. This protein change may indicate temporary effects on the blood-brain barrier, though clinical implications remain unclear.
Blood samples taken immediately after 890 MHz radiation exposure showed no significant protein changes, but transthyretin levels increased significantly when measured 60 minutes later. This delayed response pattern suggests the brain's protective barrier may need time to show measurable effects.
While a 2009 study found significant transthyretin protein increases after 890 MHz cell phone exposure, researchers explicitly stated the clinical significance remains unknown. They recommended additional randomized studies using more brain-specific markers to better understand potential health implications.